Reef dredging must stop: expert

A coral reef expert has ridiculed government claims dredging won't damage the Great Barrier Reef.

Dredging must stop to ensure the survival of one of the country's largest tourist attractions, says ARC Centre of Excellence for Coral Reef Studies director Terry Hughes.

"The stuff moves around and it certainly moves around in cyclones," Professor Hughes said on Thursday of the potentially destructive dredging spoil which will soon be allowed to be dumped near one of the world's seven natural wonders.

The Great Barrier Reef narrowly escaped being placed on the World Heritage "in danger" list last month, with UNESCO expressing concerns about dredging.

The assessment followed the federal government approving the expansion of the Abbot Point coal terminal, which will involve the dumping of millions of cubic metres of sand and silt kilometres from the reef.

The reef currently boasts just 14 per cent coral coverage on average and that will be less if dredging doesn't stop, Prof Hughes said from Canberra, where he was attending an international symposium.